There are many situations in which packages, pedestrians, vehicles and the like (conveyance) may be carrying materials which are prohibited from transport into or out of a designated area. Some examples are airports, sporting arenas and high security facilities. The prohibited materials may include, for example, explosives, drugs or even a product being stolen.
One method for screening for various materials is to individually search each conveyance for the prohibited material. Unfortunately, individual searching is extremely time-consuming and requires an inordinate number of searchers and an inordinate period of time.
It is known that many prohibited materials such as explosives and drugs emit odors which are distinctive and can be detected in very small quantities by specialized inanimate detectors which have been calibrated to identify such target odors. However, bringing expensive and often cumbersome detection equipment into direct contact with a large number of pedestrians and/or vehicles presents risks. Discrete placement of such equipment is important as well as the protection of the equipment itself, which is often expensive, and protection of personnel responsible for such equipment.
What is needed, therefore, is a reliable and consistent system to screen persons or conveyances and obtain consistent positive identifications of prohibited material while achieving, for example, some or all of the goals listed above.